The invention relates in general to a stop-leak or sealant composition and, more particularly, the invention relates to a sealant composition particularly adapted for use in the cooling systems of internal combustion engines and in hot water heating systems, although not necessarily limited thereto, which comprises leak detector additives to detect leaks that cannot be stopped by the sealant.
Stop-leak sealant compositions found in the prior art generally consist essentially of a starchy paste such as corn starch, cereal flours and the like, mixed with a powdered metal, such as aluminum, or with powdered graphite. Some compositions also contain rosins or gums, and may include in addition a small quantity of soluble oil or soap.
Such compositions function on the theory of forming a film or coating over the leaks in, for example, internal combustion engine cooling systems. Such a film or coating is generally not of a permanent nature, so that the leak may reappear after a short time, with the result that repeated treatments of the cooling system are required. Other compositions containing a soluble oil or soap have a tendency to coat the surfaces exposed to the flow of coolant or heating fluid with an oily film, so that the sealant ingredients in the composition are somewhat prevented from strongly adhering to the surfaces proximate a leak, and the oil film thus formed is detrimental to proper heat transfer between the cooling system internal surfaces and the coolant fluid circulating through the cooling system.
In U.S. Pat. No. 4,348,235, issued Sept. 7, 1982 and assigned to the same assignee as the present application, which is an improvement on prior U.S. Pat. No. 3,322,548, there is disclosed an improved stop-leak or sealant composition which avoids most of the shortcomings of prior art sealant compositions, and which further acts as an efficient rust preventer without the addition of any oil or soap to the composition, which provides a permanent seal for most holes or cracks in a cooling or heating system, which is compatible with all known types of anti-freeze compositions and which dissolves rapidly in a liquid fluid such as water and provides an improved dispersion and suspension of the ingredients in the coolant of an internal combustion engine or in the heat transferring fluid of a heating system.